In the art of injection molding and extruding plastics, it is often necessary to remove moisture from the plastic resins prior to use in a plastics forming machine. This is particularly important in situations where any moisture present in the resin can result in flaws in the formed product. Many resins used in plastic forming techniques are hygroscopic which can require many hours of drying time before use. Examples of such hygroscopic resins are nylon, acrylics, ABS (acrylonitrile-butidiene-styrene), polycarbonates and thermoplastic polyesters. An example of a device which has been developed to reduce the moisture content of such granular resins is disclosed in U.S. Pat. No. 3,875,683. The granular resin passes downwardly through the bin and dry conditioning air is forced upwardly through the resin by way of plenums located at the base and/or centrally of the bin. By forcing the dry air into the resin from the central region of the bin, a complex arrangement of plenums, collecting channels and desiccant beds for the moisture laden gases is required thereby adding to the size of the unit and complexity in structure.